/**
 * Created with IntelliJ IDEA.
 * Description:
 * User: 74646
 * Date: 2022-02-23
 * Time: 14:27
 */
import java.util.*;
class ListNode{
    int val;
    ListNode next;
    public ListNode(int val){
        this.val = val;
    }
}

class MyList{
    ListNode head;
    public void disPlay(){
        ListNode cur = this.head;
        while (cur!=null){
            System.out.print(cur.val+" ");
            cur = cur.next;
        }
        System.out.println();
    }

    public void addFist(int val){
        ListNode node = new ListNode(val);
        if(this.head==null){
            this.head = node;
        }
        node.next = head;
        head = node;
    }

}

public class Main {
    public static void main(String[] args) {

    }


    public  static String func1(String str){
        StringBuilder sb = new StringBuilder();
        for (int i = 0; i < str.length(); i++) {
            char ch = str.charAt(i);
            if(!sb.toString().contains(ch+"")){
                sb.append(ch);
            }
        }
        return sb.toString();
    }
    public static String func(String str){
        StringBuilder sb = new StringBuilder();
        int[] array = new int[58];
        for (int i = 0;i<str.length();i++){
            char ch = str.charAt(i);
            if(array[ch-65]==0){
                sb.append(ch);
                array[ch-65] = 1;
            }
        }
        return sb.toString();
    }
    public static void main1(String args[]){
        Scanner scanner = new Scanner(System.in);
        String str = scanner.nextLine();
        String ret = func(str);
        System.out.println(ret);
    }
}
